Implantable prosthetic valve with non-laminar flow

ABSTRACT

A prosthetic heart valve can include an expandable support stent, a valve assembly, and a connecting membrane. The support stent can have first and second end portions and can be configured to be radially expandable from a first configuration to a second configuration. The valve assembly can have an inlet portion, an outlet portion, and a plurality of leaflets, and the valve assembly can be supported in the support stent. The connecting membrane can be disposed radially between the support stent and the valve assembly, wherein the support stent and the valve assembly can be connected to the connecting membrane.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/991,852, filed on Jan. 8, 2016, which is a continuation of U.S.application Ser. No. 13/330,370, filed on Dec. 19, 2011, now U.S. Pat.No. 9,241,793, which is a divisional of U.S. application Ser. No.12/171,588, filed on Jul. 11, 2008, now U.S. Pat. No. 8,080,054, whichis a continuation of U.S. application Ser. No. 10/677,947, filed on Oct.2, 2003, now abandoned, the entire contents of each of which are herebyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to implantable prosthetic valves. Moreparticularly, the invention relates to a valve prosthesis for cardiacimplantation or for implantation in other body ducts where theprosthesis has improved flow characteristics,

BACKGROUND OF THE INVENTION

Several prosthetic valves are known. See, for example, U.S. Pat. No.5,411,552 (Andersen et al.), entitled VALVE PROSTHESIS FOR IMPLANTATIONIN THE BODY AND CATHETER FOR IMPLANTING SUCH VALVE PROSTHESIS, whichdiscloses a valve prosthesis comprising a stent made from an expandablecylinder-shaped thread structure comprising several spaced apices. See,also, U.S. Pat. No. 6,168,614 (Andersen et al.), entitled VALVEPROSTHESIS FOR IMPLANTATION IN THE BODY, U.S. Pat. No. 5,840,081(Andersen et al.), entitled SYSTEM AND METHOD FOR IMPLANTING CARDIACVALVES, and PCT Application No. PCT/EP97/07337 (Letac, Cribier et al.),published as WO 98/29057, entitled VALVE PROSTHESIS FOR IMPLANTATION INBODY CHANNELS, all of which are incorporated herein by reference.

In the development of stented valves, a highly desirable, and oftenpreferred design utilizes a cylindrical stent platform of either balloonexpandable or self-expanding metal designs. Usually these stents followthe cellular designs which tend to have higher radial strength and lessforeshortening than wire-wound platforms.

Such cylindrical stents offer a stable and reproducible expansionplatform for attaching valves and may be manufactured from a variety ofbiocompatible metals including stainless steels, titanium alloys,platinum-iridium, nickel-titanium alloys, chromium alloys, or tantalum.

Polymeric, bovine venous, pericardial, and porcine valve constructs havelead the early development efforts of stent-valve designs. All of theearly designs have utilized either bicuspid or tricuspid valve designs.

One of the key factors that determines the long term functionality ofstented valves is the retrograde flow characteristics. The retrogradeflow characteristics, along with the stiffness characteristics of thevalve material, will determine leakage and closing pressurerequirements. The retrograde flow characteristics are most important inlow flow/low pressure systems where the valve leaflets may thrombose inthe presence of poor retrograde laminar flow.

Stented valves are passive devices. The valves function as a result ofchanges in pressure and flow. An aortic stented valve opens passivelywhen the pressure in the left ventricle exceeds the pressure in theaorta (plus any resistance required to open the valve). The valve closeswhen the pressure in the left ventricle is less than the pressure in theaorta. However, the flow characteristics are critical to effect theclosing of the aortic valve, otherwise regurgitation will ensue.

Laminar flow is the normal condition found in most of the circulatorysystem. It is characterized by concentric layers of blood moving inparallel down the length of the blood vessel. The highest velocity isfound in the middle of the blood vessel while the lowest is found alongthe wall. The flow is parabolic in a long straight vessel under steadyflow conditions.

Non-laminar, or turbulent, flow is useful to the circulatory system. Forexample, the aortic valve opens into the sinus of Valsalva at theinferior aspect of the ascending aorta. This sinus has two keyfunctions: First, it maximizes the flow characteristics so that theaortic valve closes during diastole. And second, it optimizes coronarysinus flow and perfusion.

Laminar flow makes the retrograde flow characteristics of valves mountedin cylindrical stents problematic as the flow along the wall is least,which is central to the closing of a valve. Such laminar flow with itsattendant drawbacks is a characteristic of known stented valves. Thereis a need to have stented valves where the retrograde flowcharacteristics will be non-laminar, which will be advantageous withregard to valve closing.

SUMMARY OF THE INVENTION

According to the invention, a valve prosthesis device suitable forimplantation in body ducts comprises:

a support stent having support beams; and

a valve assembly comprising a flexible conduit having an inlet end andan outlet end, made of pliant material attached to the support beams,

wherein when flow is allowed to pass through the valve prosthesis devicefrom the inlet end to the outlet end, the valve assembly is kept in anopen position; wherein a reverse flow is prevented as portions of thevalve assembly collapse inwardly providing blockage to the reverse flow;and wherein the device is configured so that retrograde flow will bealtered from laminar flow and directed towards the leaflets to effectclosing.

In accordance with a preferred embodiment of the present invention, avalve prosthesis device suitable for implantation in body ductscomprises:

a support stent, comprised of a deployable construction adapted to beinitially crimped in a narrow configuration suitable for catheterizationthrough the body duct to a target location and adapted to be deployed byexerting substantially radial forces from within by means of adeployment device to a deployed state in the target location, thesupport stent provided with a plurality of longitudinally generallyrigid support beams of fixed length; and

a valve assembly comprising a flexible conduit having an inlet and anoutlet, made of pliant material attached to the support beams providingcollapsible slack portions of the conduit at the outlet,

wherein when flow is allowed to pass through the valve prosthesis devicefrom the inlet to the outlet, the valve assembly is kept in an openposition; wherein a reverse flow is prevented as the collapsible slackportions of the valve assembly collapse inwardly providing blockage tothe reverse flow; and wherein the device is configured so thatretrograde flow will be altered from laminar flow and directed towardsthe leaflets to effect closing.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support stent comprises an annular frame.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the expanded prosthesis comprises a sinus areaadjacent the valve assembly.

Furthermore, in accordance with another preferred embodiment of theinvention, the support stent comprises an annular frame wherein themiddle portion of the expanded annular frame extends radially to createa sinus adjacent the valve assembly.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support stent comprises an annular frame with avalve assembly arranged therein to redirect flow towards the valveassembly.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said valve assembly has a tricuspid configuration.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly is made from biocompatiblematerial.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly is made from pericardial tissue,or other biological tissue.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly is made from biocompatiblepolymers.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly is made from materials selectedfrom the group consisting of polyurethane and polyethylene terephthalate(PET).

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly comprises a main body made fromPET (polyethylene terephthalate) and leaflets made from polyurethane.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support stent is made from nickel titanium.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support beams are substantially equidistant andsubstantially parallel so as to provide anchorage for the valveassembly.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support beams are provided with bores so as toallow stitching or tying of the valve assembly to the beams.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support beams are chemically adhered to thesupport stent.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly is riveted to the support beams.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said valve assembly is sutured to the support beams.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the beams are manufactured by injection using a mold,or by machining.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly is rolled over the support stentat the inlet.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve device is manufactured using forging ordipping techniques.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly leaflets are longer than needed toexactly close the outlet, thus when they are in the collapsed statesubstantial portions of the leaflets fall on each other creating bettersealing.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly is made from coils of a polymer,coated by a coating layer of same polymer.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the polymer is polyurethane.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support stent is provided with heavy metalmarkers to enable tracking and determining the valve device position andorientation.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the heavy metal markers are selected from the groupconsisting of gold, platinum-iridium, and tantalum.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the valve assembly leaflets are provided withradio-opaque material at the outlet, to help tracking the valve deviceoperation in vivo.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the radio-opaque material comprises gold thread.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the diameter of the support stent, when fullydeployed, is in the range of from about 19 to about 26 mm.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the diameter of the support stent may be expandedfrom about 4 to about 25 mm.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support beams are provided with bores and whereinthe valve assembly is attached to the support beams by means of U-shapedrigid members that are fastened to the valve assembly and that areprovided with extruding portions that fit into matching bores on thesupport beams.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support beams comprise rigid support beams in theform of frame construction, and the valve assembly pliant material isinserted through a gap in the frame and a fastening rod is insertedthrough a pocket formed between the pliant material and the frame andholds the valve in position.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the main body of the valve assembly is made fromcoiled wire coated with coating material.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the coiled wire and the coating material is made frompolyurethane.

Furthermore, in accordance with another preferred embodiment of thepresent invention, a strengthening wire is interlaced in the valveassembly at the outlet of the conduit so as to define a fault line aboutwhich the collapsible slack portion of the valve assembly may flap.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the strengthening wire is made from nickel titaniumalloy.

Furthermore, in accordance with another preferred embodiment of thepresent invention, there is provided a valve prosthesis device suitablefor implantation in body ducts, the device comprising a main conduitbody having an inlet and an outlet and pliant leaflets attached at theoutlet so that when a flow passes through the conduit from the inlet tothe outlet the leaflets are in an open position allowing the flow toexit the outlet, and when the flow is reversed the leaflets collapse soas to block the outlet, wherein the main body is made from PET andcollapsible leaflets are made from polyurethane.

Furthermore, in accordance with another preferred embodiment of thepresent invention, support beams made from polyurethane are provided onthe main body and wherein the leaflets are attached to the main body atthe support beams.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said support beams are chemically adhered to the mainbody.

Furthermore, in accordance with another preferred embodiment of thepresent invention, there is provided a valve prosthesis device suitablefor implantation in body ducts, the device comprising:

a support stent, comprised of a deployable construction adapted to beinitially crimped in a narrow configuration suitable for catheterizationthrough the body duct to a target location and adapted to be deployed byexerting substantially radial forces from within by means of adeployment device to a deployed state in the target location, thesupport stent provided with a plurality of longitudinally rigid supportbeams of fixed length;

a valve assembly comprising a flexible conduit having an inlet end andan outlet, made of pliant material attached to the support beamsproviding collapsible slack portions of the conduit at the outlet; and

substantially equidistant rigid support beams interlaced or attached tothe slack portion of the valve assembly material, arrangedlongitudinally,

wherein the device is configured so that retrograde flow will be alteredfrom laminar flow and directed towards the leaflets to effect closing.

Furthermore, in accordance with another preferred embodiment of thepresent invention, there is provided a crimping device for crimping thevalve device described above or in the claims below, the crimping devicecomprising a plurality of adjustable plates that resemble a typical SLR(Single Lens Reflex) camera variable restrictor, each provided with ablade, that are equally dispersed in a radial symmetry but each platemoves along a line passing off an opening in the center, all platesequidistant from that center opening.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the multiple plates are adapted to movesimultaneously by means of a lever and transmission.

Furthermore, in accordance with another preferred embodiment of thepresent invention, there is provided a method for deploying animplantable prosthetic valve device from the retrograde approach(approaching the aortic valve from the descending aorta) or from theantegrade approach (approaching the aortic valve from the left ventricleafter performing a trans-septal puncture) at the natural aortic valveposition at the entrance to the left ventricle of a myocardium of apatient. This method is described in co-pending, commonly assigned U.S.patent application Ser. No. 09/975,750, filed Oct. 11, 2001, and Ser.No. 10/139,741, filed May 2, 2002, each of which is incorporated hereinby reference in its entirety.

Furthermore, in accordance with another preferred embodiment of thepresent invention, a valve prosthesis device suitable for implantationin body ducts comprises:

an expandable support frame, the support frame provided with a pluralityof longitudinally rigid support beams of fixed length; and

a valve assembly comprising a flexible conduit having an inlet end andan outlet, made of pliant material attached to the support beamsproviding collapsible slack portions of the conduit at the outlet,

wherein when flow is allowed to pass through the valve prosthesis devicefrom the inlet to the outlet, the valve assembly is kept in an openposition; wherein a reverse flow is prevented as the collapsible slackportions of the valve assembly collapse inwardly providing blockage tothe reverse flow; and wherein the device is configured so thatretrograde flow will be altered from laminar flow and directed towardsthe leaflets to effect closing.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support frame comprises a deployable constructionadapted to be initially crimped in a narrow configuration suitable forcatheterization through the body duct to a target location and adaptedto be deployed by exerting substantially radial forces from within bymeans of a deployment device to a deployed state in the target location.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support beams have a U-shaped cross section.

Furthermore, in accordance with another preferred embodiment of thepresent invention, a holder is used to secure the plaint material to thesupport beams.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support frame comprises three segments that forma circular assembly when assembled.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support beams point inwardly with respect to acentral longitudinal axis of the device.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the device is further provided with a restrictingtapered housing, for housing it in a crimped state.

Furthermore, in accordance with another preferred embodiment of thepresent invention, hooks are provided to secure the device in positionafter it is deployed.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support beams comprise longitudinal bars having anarrow slit used as the commissural attachment so that extensions thepliant material are tightly inserted through it.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the extensions of the pliant material are wrappedabout rigid bars serving as anchorage means.

Furthermore, in accordance with another preferred embodiment of thepresent invention, extensions of the pliant material are sutured to eachother at the rigid bars.

Furthermore, in accordance with another preferred embodiment of thepresent invention, a bottom portion of the pliant material is attachedto the inlet.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support beams are each provided with a roundedpole, forming a loop through which the pliant material is inserted.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the pliant material is provided with longitudinalbars attached to the pliant material at positions assigned forattachment to the support frame, in order to prevent localized stressfrom forming.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the device is further provided with longitudinal barshaving protrusions that are inserted in bores in the pliant material, asheet of PET and through bores provided on the support beams.

Furthermore, in accordance with another preferred embodiment of thepresent invention, pliant material is sutured leaving the slack portionsfree of sutures.

Furthermore, in accordance with another preferred embodiment of thepresent invention, a connecting member with a split portion is used toconnect leaflets of the pliant material to the support beams, the splitconnecting member compressing the pliant material in position.

Furthermore, in accordance with another preferred embodiment of thepresent invention, a portion of the connecting member is perpendicularto the split portion.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support frame is provided with metallic memberscoupled to the stent and rigid members are positioned on two oppositesides of the metallic member and held against each other holding portionof the pliant material between them, sutured, the metallic memberswrapped with PET.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the device is further provided with spring in orderto reduce wear of the pliant material.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the spring is provided with a spiral.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the spring is made from stainless steel.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the spring is attached to slots provided on thesupport frames.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the pliant material is sutured to the support frameforming pockets.

Furthermore, in accordance with another preferred embodiment of thepresent invention, attachment bars are provided on the stent support ata portion of the stent close to the outlet, onto which the pliantmaterial is coupled, and wherein the pliant material is attachedcircumferentially to the inlet, leaving slack pliant material.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the outlet is tapered with respect to the inlet.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support frame at the outlet is wider in diameterthan the pliant material forming the outlet.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the pliant material is reinforced using PET.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the support frame is a tube having an inner wall,having sinusoidal fold lines, wherein the pliant material is sutured tothe inner wall of the tube along suture lines.

Furthermore, in accordance with another preferred embodiment of thepresent invention, additional piece of PET is added below the suturelines.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the device is incorporated with an angioplastyballoon.

Finally, in accordance with another preferred embodiment of the presentinvention, balloon has a central longitudinal axis that runs along aflow path through the device, and a perimeter, the balloon comprisingfour inflatable portions, one portion located along a central axis andthe other three located on the perimeter, the pliant material in theform of leaflets is distributed about the perimeter.

BRIEF DESCRIPTION OF THE FIGURES

To better understand the present invention and appreciate its practicalapplications, the following Figures are provided and referencedhereafter. It should be noted that the Figures are given as examplesonly and in no way limit the scope of the invention as defined in theappended claims.

FIG. 1 represents an oblique view of an embodiment of the invention:

FIG. 2 represents a cross-sectional view across line 2-2 of theembodiment shown in FIG. 1;

FIG. 3 represents an oblique, partly cross-sectional view of anotherembodiment of the invention; and

FIG. 4 represents a cross-sectional view across line 4-4 of theembodiment shown in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

A main aspect of the present invention is the introduction of severalnovel designs for an implantable prosthetic valve. Another aspect of thepresent invention is the disclosure of several manufacturing methods forimplantable prosthetic valves in accordance with the present invention.A further aspect of the present invention is the provision of noveldeployment and positioning techniques suitable for the valve of thepresent invention.

Basically the implantable prosthetic valve of the present inventioncomprises a leaflet-valve assembly, preferably tricuspid but not limitedto tricuspid valves only, consisting of a conduit having an inlet endand an outlet, made of pliant material arranged so as to presentcollapsible walls at the outlet. The valve assembly is mounted on asupport structure or frame such as a stent adapted to be positioned at atarget location within the body duct and deploy the valve assembly bythe use of deploying means, such as a balloon catheter or similardevices. In embodiments suitable for safe and convenient percutaneouspositioning and deployment the annular frame is able to be posed in twopositions, a crimped position where the conduit passage cross-sectionpresented is small so as to permit advancing the device towards itstarget location, and a deployed position where the frame is radialextended by forces exerted from within (by deploying means) so as toprovide support against the body duct wall, secure the valve in positionand open itself so as to allow flow through the conduit.

The valve assembly can be made from biological matter, such as a naturaltissue, pericardial tissue or other biological tissue. Alternatively,the valve assembly may be made form biocompatible polymers or similarmaterials. Homograph biological valves need occasional replacement(usually within 5 to 14 years), and this is a consideration the surgeonmust take into account when selecting the proper valve implant accordingto the patient type. Mechanical valves, which have better durabilityqualities, carry the associated risk of long-term anticoagulationtreatment.

The frame can be made from shape memory alloys such as nickel titanium(nickel titanium shape memory alloys, or NiTi, as marketed, for example,under the brand name Nitinol), or other biocompatible metals. Thepercutaneously implantable embodiment of the implantable valve of thepresent invention has to be suitable for crimping into a narrowconfiguration for positioning and expandable to a wider, deployedconfiguration so as to anchor in position in the desired targetlocation.

The support stent is preferably annular, but may be provided in othershapes too, depending on the cross-section shape of the desired targetlocation passage.

Manufacturing of the implantable prosthetic valve of the presentinvention can be done in various methods, by using pericardium or, forexample, by using artificial materials made by dipping, injection,electrospinning, rotation, ironing, or pressing.

The attachment of the valve assembly to the support stent can beaccomplished in several ways, such as by sewing it to several anchoringpoints on the support frame or stent, or riveting it, pinning it,adhering it, or welding it, to provide a valve assembly that is cast ormolded over the support frame or stent, or use any other suitable way ofattachment.

To prevent leakage from the inlet it is optionally possible to roll upsome slack wall of the inlet over the edge of the frame so as to presentrolled-up sleeve-like portion at the inlet.

Furthermore, floating supports may be added to enhance the stability ofthe device and prevent it from turning inside out.

An important aspect of certain embodiments of the present invention isthe provision of rigid support beams incorporated with the support stentthat retains its longitudinal dimension while the entire support stentmay be longitudinally or laterally extended.

The aforementioned embodiments as well as other embodiments,manufacturing methods, different designs and different types of devicesare discussed and explained below with reference to the accompanyingdrawings. Note that the drawings are only given for the purpose ofunderstanding the present invention and presenting some preferredembodiments of the present invention, but this does in no way limit thescope of the present invention as defined in the appended claims.

FIGS. 1 and 2 illustrate a general tricuspid implantable prostheticvalve 10 in accordance with a preferred embodiment of the presentinvention, suitable for percutaneous deployment using an expandablestent or similar deploying means, shown in its deployed position. Valve10 comprises a valve assembly 20 having an inlet 22 and an outlet 24,the outlet walls consisting of collapsible pliant leaflet material 26that is arranged to collapse in a tricuspid arrangement. Valve assembly20 is attached to an annular support stent 32, the one in this figurebeing a net-like frame designed to be adapted to crimp evenly so as topresent a narrow configuration and be radially deployable so as toextend to occupy the passage at the target location for implantation ina body duct. Support beams 34 are provided on annular support stent 32to provide anchorage to valve assembly 20. Support beams 34 areoptionally provided with bores 36 to allow stitching of valve assembly20 to support beams 34 by thread, wire, or other attachment means.

The proximal portion 38 of support stent 32 is snuggly fit or fastenedto the proximal portion of valve assembly 20 so that any flow is onlyinto inlet 22. In the particular embodiment depicted, the proximalportion of the valve assembly 20 is rolled over the support stent 32 atthe inlet 22, thereby forming a rolled-up sleeve-like portion 21 thatprevents leakage. Optionally the radial sections 23 of each leaflet 26are closed by stitching, gluing or other means to narrow outlet 24 whileleaving the slack portions 25 free. The distal portion 42 of supportstent 32 is narrower than proximal portion 38. The combination of theeffect on flow characteristics due to the narrowing of support stent 32and the narrowing of outlet 24 is sufficient to engender the desiredeffect or flow characteristics, namely, non-laminar retrograde flow thatwill assist in the closing of leaflets 26.

Another embodiment of the invention is shown in FIGS. 3 and 4. Aprosthetic valve 50 comprises a valve assembly 52 positioned within asupport stent 54. The proximal 56 and distal 58 portions of supportstent 54 are narrow as compared to the mid-portion 60 of support stent54, where valve assembly 52 is positioned. Within support stentmid-portion 60 valve assembly 52 is preferably positioned co-axially andat a small distance, for example, from 0.5 to 3 cm, from the interiorsurface 64 of support stent 54. Valve assembly 52 is attached byconnecting membrane 66 to stent supports 68, which optimally have holesor projections 70 to anchor said membranes 66. Any annular space betweeninterior surface 64 and valve assembly 52 is filled with appropriatematerial to prevent flow around valve assembly 52. Valve leaflets areshown in closed 72 and open 74 positions.

The effective cross-sectional area of valve assembly 52 will preferablybe from about 40 to 80% of the cross-sectional area across support stentmidsection 60.

The preferred embodiments representing an implantable prosthetic valvein accordance with the present invention are relatively easy tomanufacture as they are generally flat throughout most of the productionprocess and only at the final stage of mounting the other elements ofthe valve assembly on the support frame, a three dimensional form isestablished.

A typical size of an aortic prosthetic valve is from about 19 to about26 mm in diameter. A maximal size of a catheter inserted into thefemoral artery should be no more than 9 mm in diameter. The presentinvention introduces a device, which has the ability to change itsdiameter from about 4 mm to about 26 mm. Artificial valves are not new;however, artificial valves in accordance with the present inventionpossess the ability to change shape and size for the purpose of deliveryand as such are novel. These newly designed valves require newmanufacturing methods and technical inventions and improvements, some ofwhich were described herein.

As mentioned earlier, the material of which the valve is made from canbe either biological or artificial. In any case new technologies areneeded to create such a valve.

To attach the valve to the body, the blood vessels determine the sizeduring delivery, and the requirements for it to work efficiently, thereis a need to mount it on a collapsible construction which can be crimpedto a small size, be expanded to a larger size, and be strong enough toact as a support for the valve function. This construction, which is insomewhat similar to a large “stent”, can be made of different materialssuch as Nitinol, biocompatible stainless steel, polymeric material or acombination of all. Special requirement for the stent are a subject ofsome of the embodiments discussed herein.

The mounting of the valve onto a collapsible stent is a new field ofproblems. New solutions to this problem are described herein.

Another major aspect of the design of the valve of the present inventionis the attachment to the body.

In the traditional procedure the valve is sutured in place by acomplicated suturing procedure. In the case of the percutaneousprocedure there is no direct access to the implantation site thereforedifferent attachment techniques are needed.

Another new problem that is dealt herein is the delivery procedure,which is new and unique. Positioning of the device in the body in anaccurate location and orientation requires special marking and measuringmethods of the device and surgical site as was disclosed herein.

Artificial polymer valves require special treatment and specialconditions when kept on a shelf, as well as a special sterilizationprocedure. One of the consequences of the shelf treatment is the need tocrimp the valve during the implantation procedure. A series of devicesand inventions to allow the crimping procedure are disclosed herein.

It should be clear that the description of the embodiments and attachedFigures set forth in this specification serves only for a betterunderstanding of the invention, without limiting its scope as covered bythe following claims.

It should also be clear that a person skilled in the art, after readingthe present specification could make adjustments or amendments to theattached Figures and above described embodiments that would still becovered by the following claims.

What is claimed is:
 1. A prosthetic heart valve, comprising: anexpandable support stent having first and second end portions, whereinthe support stent is configured to be radially expandable from a firstconfiguration to a second configuration; a valve assembly having aninlet portion, an outlet portion, and a plurality of leaflets, whereinthe valve assembly is supported in the support stent; and a connectingmembrane extending radially inwardly from the support stent to the valveassembly, wherein the support stent and the valve assembly are connectedto the connecting membrane.
 2. The prosthetic heart valve of claim 1,wherein the connecting membrane has an inner edge connected to the valveassembly and an outer edge connected to the support stent.
 3. Theprosthetic heart valve of claim 2, wherein the outer edge of theconnecting membrane is connected to the support stent with stitching. 4.The prosthetic heart valve of claim 1, wherein an annular space isdefined between the inner surface of the support stent and the outersurface of the valve assembly, and sealing material is disposed in theannular spaced to prevent blood from flowing around the valve assembly.5. The prosthetic heart valve of claim 1, wherein the firstconfiguration is a crimped configuration and the second configuration isa deployed configuration, and the valve assembly is spaced radiallyinwardly from the support stent by 0.5 cm to 3 cm when the support stentis in the deployed configuration.
 6. The prosthetic heart valve of claim1, wherein the support stent further comprises a mid-portion disposedaxially between the first and second end portions and comprises alongitudinal axis extending from the first end portion to the second endportion, the support stent and the valve assembly each have across-sectional area taken in a plane that is perpendicular to thelongitudinal axis of the support stent at the mid-portion of the supportstent, and the cross-sectional area of the valve assembly is 40-80percent of the cross-sectional area of the support stent when thesupport stent is in the deployed configuration.
 7. The prosthetic heartvalve of claim 1, wherein the inlet portion of the valve assemblyextends radially outwardly to the first end portion of the supportstent, thereby reducing blood flow around the valve assembly.
 8. Theprosthetic heart valve of claim 1, wherein the support stent furthercomprises a mid-portion disposed axially between the first and secondend portions, and the mid-portion of the support stent is radiallylarger than the first end second end portions when the support stent isin the deployed configuration.
 9. The prosthetic heart valve of claim 1,wherein the first end portion of the support stent is radially largerthan the second end portion of the support stent when the support stentis in the deployed configuration.
 10. The prosthetic heart valve ofclaim 1, wherein the connecting membrane extends from the inlet portionto the outlet portion of the valve assembly.
 11. The prosthetic heartvalve of claim 1, wherein the inlet portion and the outlet portion ofthe valve assembly are spaced radially inwardly of the support stent bythe connecting membrane.
 12. The prosthetic heart valve of claim 1,wherein the leaflets form a plurality of commissures and the connectingmembrane comprises a connecting membrane positioned adjacent eachcommissure, each connecting membrane extending from the support stent toan adjacent commissure.
 13. A prosthetic heart valve, comprising: anexpandable support stent having a first end portion and a second endportion, wherein the support stent is configured to be radiallyexpandable from a first, crimped configuration for catheterization intoa patient's body to a second, expanded configuration; a valve assemblyhaving an inlet end, an outlet end, and a plurality of leaflets, whereinthe valve assembly is supported in the support stent, wherein theleaflets are configured to permit blood to flow through the valveassembly in a direction from the first end portion to the second endportion of the frame and block the flow of blood in the reversedirection; and wherein an annular spaced is defined between an interiorof the support stent and the valve assembly at the inlet end of thevalve assembly when the support stent is in the second configuration.14. The prosthetic heart valve of claim 13, further comprising sealingmaterial disposed in the annular spaced to prevent blood from flowingaround the valve assembly.
 15. The prosthetic heart valve of claim 13,further comprising a connecting membrane extending radially inwardlyfrom the support stent to the valve assembly, wherein the support stentand the valve assembly are connected to the connecting membrane.
 16. Theprosthetic heart valve of claim 13, wherein the support stent tapersfrom the first end portion to the second end portion.
 17. The prostheticheart valve of claim 13, wherein the support stent includes amid-portion disposed axially between the first and second end portions,and the first and second end portions are radially smaller than themid-portion.
 18. The prosthetic heart valve of claim 13, wherein theannular space extends from the inlet end to the outlet end of the valveassembly.
 19. A prosthetic heart valve, comprising: an expandablesupport stent having first and second end portions, wherein the supportstent is configured to be radially expandable from a first configurationto a second configuration; a valve assembly having an inlet end, anoutlet end, and a plurality of leaflets joined together at commissures,wherein the valve assembly is supported in the support stent; and aplurality of connecting membranes at least partially disposed radiallybetween the support stent and the valve assembly, wherein each of theconnecting membranes is disposed adjacent a respective commissure of theleaflets, and each of the connecting membranes is connected to thesupport stent and the valve assembly at an adjacent commissure.
 20. Theprosthetic heart valve of claim 19, wherein the inlet end and the outerend of the valve assembly are spaced radially inwardly of the supportstent by the connecting membranes.